Creative and experimental choreographer and dancer considered the most influential figure in 20th-century dance. Balanchine's career began in Russia, where he was a student at the Imperial Ballet School. He danced with and choreographed Diaghilev's Ballets Russes before coming to the United States, where he became ballet director of the Metropolitan Opera (1934–37), co-founder with Lincoln Kirstein of the School of American Ballet (1934) and principal choreographer of the New York City Ballet. He created more than 200 dances for the NYCB, including Serenade and Don Quixote.